| 摘要 |
PURPOSE:To form an accurate alignment mark by a method wherein a mask having a window in the part excluding the element forming region is formed on an Si substrate and then the substrate is etched from the window using an etchant in different etching rate to the substrate surface. CONSTITUTION:An SiO2 film as a masking material 21 is formed by CVD process on a(100) Si substrate 1 and then a cross window 3 is formed assuming the (011) direction and the perpendicular direction to the (011) direction as the outer frame of the window 3. When the window 3 is etched using potassium hydroxide as an etchant, the (111) surface is exposed finally to form a V shape groove comprising (111) surface by further advancing the etching process. A cross alignment mark comprising the (111) surface is completed when the mask 2 is removed. When an epitaxial layer is deposited on the mark, the (111) surface to be easily exposed in the epitaxial depositing process is deposited perpendicular to the (100) surface by holding the original shape. Through these procedures, a clear alignment mark to be easily detected can be formed on the Si substrate. |
